Locking device for shafts of clockworks



Jan. 6, 1931.

H. JUNGHANS 1,788,110

LOCKING DEVICE FOR SHAFTS OF CLOCKWORKS Filed Aug. 6, 1928 Inventor: HeZmuZ Juvz kaxns y I v AZZoFwey Patented Jan. 6, 1931 1,7sa 11e HELMUT JUNGHANS, onscrraniyrnnne, GERMANY ,l I

nocxme DEVICE non snan'isor onoc'xwonxs' Application filed August 6, 1928, Serial No. 297,901, and in German; A pril 19, 1928.

My invention pertains to locking devices for the shafts of clockworks and similar mechanisms and more particularly to an img proved device for locking the gripping shaft 5 of a clockwork employed in kinematographic apparatus, and which shaft is adapted and arranged to accomplish connections or controlling operations periodically or in predetermined intervals. Shafts of this kind are provided, for certain known reasons, with centrifugal or fly-wheel masses and, if a shaft of a clockwork, as above stated, shallbe arrested and fixed each time exactly in the same posi-:; tion, it is not suificient'to let the shaft which 15 usually revolves with considerable speed and momentum, strike against a looking or ar-;

resting lever even with a certain advance,

since particularly under the action of the centrifugal or fly-wheel body the shaft will fly 20 back for a certain amount in case of an abrupt stop which is highly objectionable.

The object of my invention is to remove this disadvantage and with this object in view I n so construct and arrange the locking or ar resting lever that the same will be adapted to directly engage and arrest the centrifugal or fly-wheel mass or body. To this end I preferably shape the lever to form a pawl or detent adapted to catch intoa dwell provided 0 in the centrifugal body whereby the shaft will be momentarily arrested and safely locked and at the same time prevented from flying back, since the centrifugal body, prefr erably of cylindrical shape, is rigidly connected or integral with the shaft.

Having thus set forth in general the principles upon which my invention depends and having shown in particular the improvements effected over the prior art, I shall. now particularly describe one simple embodiment thereof which I have shown diagrammatically in the accompanying drawings for the purpose of more fully disclosing my invention; but it is to be understood that such diagram shows only one of the several possible embodiments of my invention which I have successfully used in practice and that I do not limit myself thereto inasmuch as many modi- 0 fications may be devised by those skilled in RI E the art without departing from the spirit and scope of my invention. p I 1 In the accompanying drawingsforming a part of this specification andshowing for purposes of exemplificationonly a preferr 5.

formand manner in which the invention may be performed and practised. Y

Figure 1 is a front view ofthe centrifugal body secured to the shaft whichis broken away; Figure 2 is a side view thereof, and

Figure 3-isap'lan view thereof. Before'proceeding'to describe the specific constructionlof the locking device-I wish to have it understood that though the essential -feature of my invention resides in the provision of anotchI-shaped dwell inthe peripheral face or an end face of a cylindrical centrifugalor fly-wheel body for the pawl-like detent to engage therein, still I prefer to combine such a notch or dwell with a helicoid guiding groove in the'rperipheral or end face of the centrifugal body for the detent to slide and gradually descend therein prior to its catching'into the notch when'the rotation of the shaft is to be stopped.

In the embodiment shown the centrifugal body?) is of cylindrical shape and firmly connected with the shaft a in any suitable manner. The hook-shaped pawl c is pivotally attached to some stationary member (not shown) andadapted to co-operate with the body 6 for the purpose of locking the shaft (1. To this end the body I) is provided with a recess or notch shapedto conform to the shape of the hook or nose d ofthe pawl, and located at a point corresponding to the requirement of stopping the shaft.

In the sectional plane ofthe notch there is cut'a peripheral recess or groove of helicoid configuration extendingfrom the wall 9 of tion illustrated in Figure 2 the nose 01 thereof lies in the notch between the two walls 9 and h thereof. The wall or shoulder it constitutes the face against which the nose (I abuts for locking the shaft revolving in the direction 7 indicated by an arrow in Figure 2, while the wall or shoulder g of the notch will lock the shaft with regard to the opposite moving direction. Consequently the Operation of the locking device is such that when the shaft rotates siir-theaiirection of'thearrowithe pawl will slidesonthe helicoid bottom of therecess f until it drops into the notch and atthesame. n time strikes against thewall h thereof, so that the shaft will be lok'ed'and att'hesametime' prevented from flyingfihack due to .thelimit. ing resistance ofieredby the rear Wall g ofthe notch. l, I V 7 H u I have described with great particularity 20f detailiazcertainaspecific.embodiment-ofany I invention only, but Iaaim:in'itheeappended :claim to embrace tall xmodificati'ons :.;faJ11ing tfiairlyiwithin the: scopesof myginvention. 3o WhatfI c1aim:is::-- e

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ilfntes'timonywhereoffl afiixnny signature. v :HELMUTmIUNGHANS-.- 

